const express = require('express');
const jianSunDb = require('../config/jianSunDatabase');
const middleDb = require('../config/middlePlatformDatabase');

const router = express.Router();

const MAX_PAGE_SIZE = 100;

function safeInt(value, fallback) {
  const parsed = Number.parseInt(value, 10);
  return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
}

function toNum(value) {
  const n = Number(value);
  return Number.isFinite(n) ? n : 0;
}

function fmtMoney(value) {
  const n = Number(value);
  return Number.isFinite(n) ? n.toFixed(2) : '-';
}

function fmtRate(value) {
  const n = Number(value);
  return Number.isFinite(n) ? (n * 100).toFixed(2) : '-';
}

function fmtNum(value) {
  const n = Number(value);
  return Number.isFinite(n) ? n.toLocaleString('zh-CN') : '-';
}

function getDateRange(period, customStart, customEnd) {
  const now = new Date();
  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());

  switch (period) {
    case 'realtime': {
      const d = new Date(today);
      return { start: formatDate(d), end: formatDate(d) };
    }
    case 'yesterday': {
      const d = new Date(today);
      d.setDate(d.getDate() - 1);
      return { start: formatDate(d), end: formatDate(d) };
    }
    case 'week': {
      const d = new Date(today);
      d.setDate(d.getDate() - d.getDay() + (d.getDay() === 0 ? -6 : 1));
      return { start: formatDate(d), end: formatDate(today) };
    }
    case 'month': {
      const d = new Date(today.getFullYear(), today.getMonth(), 1);
      return { start: formatDate(d), end: formatDate(today) };
    }
    case 'last7d': {
      const d = new Date(today);
      d.setDate(d.getDate() - 6);
      return { start: formatDate(d), end: formatDate(today) };
    }
    case 'last30d': {
      const d = new Date(today);
      d.setDate(d.getDate() - 29);
      return { start: formatDate(d), end: formatDate(today) };
    }
    case 'custom': {
      return {
        start: customStart || formatDate(today),
        end: customEnd || formatDate(today),
      };
    }
    default: {
      const d = new Date(today);
      d.setDate(d.getDate() - 6);
      return { start: formatDate(d), end: formatDate(today) };
    }
  }
}

function formatDate(d) {
  const y = d.getFullYear();
  const m = String(d.getMonth() + 1).padStart(2, '0');
  const day = String(d.getDate()).padStart(2, '0');
  return `${y}-${m}-${day}`;
}

// 环比：取紧邻上一段等长周期（如近7天 → 再往前7天；自定义区间 → 等长前移）
function getPreviousRange(range) {
  const start = new Date(`${range.start}T00:00:00`);
  const end = new Date(`${range.end}T00:00:00`);
  if (Number.isNaN(start.getTime()) || Number.isNaN(end.getTime())) {
    return null;
  }
  const lengthDays = Math.max(1, Math.round((end - start) / 86400000) + 1);
  const prevEnd = new Date(start);
  prevEnd.setDate(prevEnd.getDate() - 1);
  const prevStart = new Date(prevEnd);
  prevStart.setDate(prevStart.getDate() - (lengthDays - 1));
  return { start: formatDate(prevStart), end: formatDate(prevEnd) };
}

const PROMOTION_SUMMARY_SELECT = `SELECT
  COUNT(*) AS totalRecords,
  SUM(TRY_CONVERT(decimal(18,2), [orderSpend])) / 1000.0 AS totalOrderSpend,
  SUM(TRY_CONVERT(decimal(18,2), [gmv])) / 1000.0 AS totalGmv,
  CASE WHEN SUM(TRY_CONVERT(decimal(18,2), [orderSpend])) > 0
    THEN SUM(TRY_CONVERT(decimal(18,2), [gmv])) / SUM(TRY_CONVERT(decimal(18,2), [orderSpend]))
    ELSE 0 END AS avgRoi,
  SUM(TRY_CONVERT(decimal(18,2), [spend])) / 1000.0 AS totalSpend,
  SUM(TRY_CONVERT(decimal(18,2), [netGmv])) / 1000.0 AS totalNetGmv,
  CASE WHEN SUM(TRY_CONVERT(decimal(18,2), [orderSpend])) > 0
    THEN SUM(TRY_CONVERT(decimal(18,2), [netGmv])) / SUM(TRY_CONVERT(decimal(18,2), [orderSpend]))
    ELSE 0 END AS avgNetRoi,
  SUM(TRY_CONVERT(int, [netOrderNum])) AS totalNetOrderNum,
  CASE WHEN SUM(TRY_CONVERT(int, [netOrderNum])) > 0
    THEN SUM(TRY_CONVERT(decimal(18,2), [orderSpend])) / 1000.0 / SUM(TRY_CONVERT(int, [netOrderNum]))
    ELSE 0 END AS avgCostPerNetOrder
 FROM dbo.pdd_ReportGoodsSpread
 WHERE LEFT([createTime], 10) >= @startDate AND LEFT([createTime], 10) <= @endDate`;

async function queryPromotionSummary(range) {
  const [row] = await jianSunDb.query(PROMOTION_SUMMARY_SELECT, {
    startDate: range.start,
    endDate: range.end,
  });
  const stats = row || {};
  return {
    totalRecords: toNum(stats.totalRecords),
    orderSpend: toNum(stats.totalOrderSpend),
    gmv: toNum(stats.totalGmv),
    roi: toNum(stats.avgRoi),
    spend: toNum(stats.totalSpend),
    netGmv: toNum(stats.totalNetGmv),
    netRoi: toNum(stats.avgNetRoi),
    netOrderNum: toNum(stats.totalNetOrderNum),
    costPerNetOrder: toNum(stats.avgCostPerNetOrder),
  };
}

// 环比变化率：(当前 - 上一周期) / |上一周期|，上一周期为 0 时返回 null
function buildPeriodChanges(current, previous) {
  const changes = {};
  Object.keys(current).forEach((key) => {
    const base = Math.abs(previous[key]);
    changes[key] = base > 0 ? (current[key] - previous[key]) / base : null;
  });
  return changes;
}

async function getImageMap(goodsIds) {
  if (!goodsIds.length) return new Map();
  try {
    const placeholders = goodsIds.map((_, i) => `@gid${i}`).join(',');
    const params = {};
    goodsIds.forEach((id, i) => { params[`gid${i}`] = String(id); });
    const rows = await middleDb.query(
      `SELECT DISTINCT CONVERT(varchar(50), goodsId) AS goodsId, hdThumbUrl
       FROM dbo.pdd_DataGoods
       WHERE CONVERT(varchar(50), goodsId) IN (${placeholders})`,
      params
    );
    const map = new Map();
    rows.forEach((row) => {
      if (row.hdThumbUrl) map.set(String(row.goodsId), row.hdThumbUrl);
    });
    return map;
  } catch {
    return new Map();
  }
}

router.get('/latest-date', async (req, res) => {
  try {
    const rows = await jianSunDb.query(
      `SELECT DISTINCT TOP 2 LEFT([createTime], 10) AS createDate
       FROM dbo.pdd_ReportGoodsSpread
       WHERE [createTime] IS NOT NULL AND LTRIM(RTRIM([createTime])) != ''
       ORDER BY createDate DESC`
    );
    const date = rows.length >= 2 ? rows[1].createDate : (rows[0]?.createDate || '');
    res.json({ success: true, data: { date: String(date || '').trim() } });
  } catch (error) {
    console.error('[PromotionModule] 查询最新数据日期失败:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.get('/shops', async (req, res) => {
  try {
    const rows = await jianSunDb.query(
      `SELECT DISTINCT [shopName]
       FROM dbo.pdd_ReportGoodsSpread
       WHERE [shopName] IS NOT NULL AND LTRIM(RTRIM([shopName])) != ''
       ORDER BY [shopName]`
    );
    res.json({ success: true, data: rows.map((r) => r.shopName) });
  } catch (error) {
    console.error('[PromotionModule] 查询店铺列表失败:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.get('/summary', async (req, res) => {
  try {
    const { date, period, start: customStart, end: customEnd } = req.query;
    let filterDate = (date && String(date).trim()) || '';
    let range;

    if (period === 'custom') {
      range = getDateRange('custom', customStart, customEnd);
    } else if (period) {
      range = getDateRange(period);
      filterDate = '';
    }

    if (!range) {
      // 单日口径：未带 period 时按最新数据日（默认取倒数第二个有数据的日期）
      if (!filterDate) {
        const dateRows = await jianSunDb.query(
          `SELECT DISTINCT TOP 2 LEFT([createTime], 10) AS createDate
           FROM dbo.pdd_ReportGoodsSpread
           WHERE [createTime] IS NOT NULL AND LTRIM(RTRIM([createTime])) != ''
           ORDER BY createDate DESC`
        );
        filterDate = dateRows.length >= 2
          ? String(dateRows[1].createDate || '').trim()
          : String(dateRows[0]?.createDate || '').trim();
      }
      range = { start: filterDate, end: filterDate };
    }

    const previousRange = getPreviousRange(range);
    const [current, previous] = await Promise.all([
      queryPromotionSummary(range),
      previousRange ? queryPromotionSummary(previousRange) : Promise.resolve(null),
    ]);

    res.json({
      success: true,
      data: {
        filterDate: `${range.start} ~ ${range.end}`,
        previousRange: previousRange ? `${previousRange.start} ~ ${previousRange.end}` : '',
        totalRecords: current.totalRecords,
        orderSpend: fmtMoney(current.orderSpend),
        gmv: fmtMoney(current.gmv),
        roi: fmtNum(current.roi),
        spend: fmtMoney(current.spend),
        netGmv: fmtMoney(current.netGmv),
        netRoi: fmtNum(current.netRoi),
        netOrderNum: fmtNum(current.netOrderNum),
        costPerNetOrder: fmtMoney(current.costPerNetOrder),
        changes: previous ? buildPeriodChanges(current, previous) : null,
      },
    });
  } catch (error) {
    console.error('[PromotionModule] 查询汇总数据失败:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.get('/list', async (req, res) => {
  try {
    const {
      page = 1,
      pageSize = 20,
      sortBy = 'orderSpend',
      sortOrder = 'DESC',
      keyword,
      shopName,
      date,
      period,
      start: customStart,
      end: customEnd,
    } = req.query;

    const currentPage = safeInt(page, 1);
    const limit = Math.min(safeInt(pageSize, 20), MAX_PAGE_SIZE);
    const offset = (currentPage - 1) * limit;

    const whereParts = [];
    const params = {};

    if (period && period !== 'custom') {
      const range = getDateRange(period);
      whereParts.push('LEFT([createTime], 10) >= @startDate AND LEFT([createTime], 10) <= @endDate');
      params.startDate = range.start;
      params.endDate = range.end;
    } else if (period === 'custom' && customStart && customEnd) {
      whereParts.push('LEFT([createTime], 10) >= @startDate AND LEFT([createTime], 10) <= @endDate');
      params.startDate = customStart;
      params.endDate = customEnd;
    } else {
      let filterDate = (date && String(date).trim()) || '';
      if (!filterDate) {
        const dateRows = await jianSunDb.query(
          `SELECT DISTINCT TOP 2 LEFT([createTime], 10) AS createDate
           FROM dbo.pdd_ReportGoodsSpread
           WHERE [createTime] IS NOT NULL AND LTRIM(RTRIM([createTime])) != ''
           ORDER BY createDate DESC`
        );
        filterDate = dateRows.length >= 2
          ? String(dateRows[1].createDate || '').trim()
          : String(dateRows[0]?.createDate || '').trim();
      }
      if (filterDate) {
        whereParts.push('LEFT([createTime], 10) = @filterDate');
        params.filterDate = filterDate;
      }
    }

    if (keyword && keyword.trim()) {
      whereParts.push('([goodsName] LIKE @kw OR [goodsId] LIKE @kw)');
      params.kw = `%${keyword.trim()}%`;
    }
    if (shopName && shopName.trim()) {
      whereParts.push('[shopName] = @shopName');
      params.shopName = shopName.trim();
    }

    const whereSql = whereParts.length > 0 ? `WHERE ${whereParts.join(' AND ')}` : '';

    const allowedSort = new Set([
      'goodsName', 'goodsId', 'shopName', 'createTime', 'orderSpend', 'gmv', 'roi',
      'spend', 'orderNum', 'netGmv', 'netRoi', 'netOrderNum', 'netAvgPayAmount',
      'settlementGmv', 'settlementRoi', 'settlementOrder', 'impression', 'click', 'ctr', 'cvr',
    ]);
    const sortCol = allowedSort.has(sortBy) ? `[${sortBy}]` : '[orderSpend]';
    const sortDir = String(sortOrder || '').toLowerCase() === 'asc' ? 'ASC' : 'DESC';

    const countResult = await jianSunDb.query(
      `SELECT COUNT(*) AS total FROM dbo.pdd_ReportGoodsSpread ${whereSql}`,
      params
    );
    const total = countResult[0]?.total || 0;

    const dataResult = await jianSunDb.query(
      `SELECT
        [id],
        [goodsName],
        [goodsId],
        [shopName],
        [createTime],
        [orderSpend],
        [gmv],
        [roi],
        [spend],
        [orderNum],
        [transactionCost],
        [avgPayAmount],
        [directGmv],
        [indirectGmv],
        [directOrderNum],
        [indirectOrderNum],
        [netGmv],
        [netRoi],
        [netOrderNum],
        [netAvgPayAmount],
        [netRate],
        [settlementGmv],
        [settlementRoi],
        [settlementOrder],
        [refundGmvRate30d],
        [refundOrderRate30d],
        [exemptRefundGmvRate30d],
        [exemptRefundOrderRate30d],
        [settlementGmvRate],
        [settlementOrderRate],
        [costPerSettlementOrderForDeal],
        [impression],
        [click],
        [ctr],
        [cvr],
        [targetRoi],
        [targetBid]
       FROM dbo.pdd_ReportGoodsSpread
       ${whereSql}
       ORDER BY ${sortCol} ${sortDir}
       OFFSET @offset ROWS FETCH NEXT @limit ROWS ONLY`,
      { ...params, offset, limit }
    );

    const goodsIds = dataResult.map((r) => String(r.goodsId)).filter(Boolean);
    const imageMap = await getImageMap(goodsIds);

    const list = dataResult.map((row) => ({
      ...row,
      thumbUrl: imageMap.get(String(row.goodsId)) || '',
      orderSpend: row.orderSpend != null ? toNum(row.orderSpend) / 1000.0 : null,
      gmv: row.gmv != null ? toNum(row.gmv) / 1000.0 : null,
      spend: row.spend != null ? toNum(row.spend) / 1000.0 : null,
      transactionCost: row.transactionCost != null ? toNum(row.transactionCost) / 1000.0 : null,
      avgPayAmount: row.avgPayAmount != null ? toNum(row.avgPayAmount) / 1000.0 : null,
      directGmv: row.directGmv != null ? toNum(row.directGmv) / 1000.0 : null,
      indirectGmv: row.indirectGmv != null ? toNum(row.indirectGmv) / 1000.0 : null,
      netGmv: row.netGmv != null ? toNum(row.netGmv) / 1000.0 : null,
      netAvgPayAmount: row.netAvgPayAmount != null ? toNum(row.netAvgPayAmount) / 1000.0 : null,
      settlementGmv: row.settlementGmv != null ? toNum(row.settlementGmv) / 1000.0 : null,
      costPerSettlementOrderForDeal: row.costPerSettlementOrderForDeal != null ? toNum(row.costPerSettlementOrderForDeal) / 1000.0 : null,
    }));

    res.json({
      success: true,
      data: {
        list,
        total,
        page: currentPage,
        pageSize: limit,
      },
    });
  } catch (error) {
    console.error('[PromotionModule] 查询推广数据失败:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

module.exports = router;